[Event "New to nuke: Rook invasions: Exercise: lack of space"]
[Site "https://lichess.org/study/2lC2jkJj/RNJ147Bm"]
[Result "*"]
[Variant "Atomic"]
[ECO "?"]
[Opening "?"]
[Annotator "https://lichess.org/@/Illion"]
[FEN "4k3/2p3p1/8/5p2/8/8/8/3RK3 w - - 0 1"]
[SetUp "1"]
[UTCDate "2017.09.13"]
[UTCTime "23:30:21"]
[Source "https://lichess.org/study/2lC2jkJj/RNJ147Bm"]
[Orientation "white"]
[ChapterMode "gamebook"]
{ White to play. Applying the 2x2 rule, black doesn't have a safe 2x2 square, so isn't immediately safe. However, can you find a way to actually mate black or is it a draw? } { [%csl Gd8,Ge7,Gf8,Gd6,Ge8,Ge6][%cal Rc7c8,Rc7c6,Rc7d7,Rg7f7,Rg7g8,Rf5f6,Rf5e5] }
1. Rd8+ (1. Rd7? { Black can make a safe 2x2 square by pushing the c- or g-pawns. } 1... c5 $10 { [%csl Gd8,Gd7,Ge7,Ge8] }) 1... Ke7 2. Rd7+ (2. Re8+? { Black can escape into open space with 2...Kd6. } 2... Kd6 { [%csl Gd5,Gc5,Gc4,Gd4] }) 2... Ke6 { Black is close to the free space on d5-d4-c5-c4. White now needs to pick the correct threat to make the black king retreat back among its pawns. } 3. Rd6+ { This check keeps black's king in the middle of its pawns. If 3...Ke5, 4. Rd5+ forms the mating pattern. } (3. Rd5? { This attacks the f-pawn, but black makes a safe 2x2 square (d6, e6, d5, e5) with 3...f4. } 3... f4 { [%csl Ge6,Gd6,Gd5,Ge5] }) (3. Rf7? { Black can escape into open space with 3...Kd5. } 3... Kd5 { [%csl Gd5,Gc5,Gc4,Gd4] }) (3. Re7+? { Black can escape into open space with 3...Kd5. } 3... Kd5 { [%csl Gd4,Gc5,Gd5,Gc4] }) 3... Ke7 4. Re6+ Kd8 5. Re8+ (5. Re7? { This attacks the c-pawn, but black can respond to the threat and make a safe 2x2 square with 5...c5. } 5... c5 { [%csl Gd8,Gd7,Ge8,Ge7] }) 5... Kd7 6. Re7+ Kc6 7. Rxc7# { Correct! You have solved the exercise. } *